The objectives of the proposed research are to establish animal models of ocular lymphoproliferative and granulomatous inflammation, such as orbital pseudotumors and follicular conjunctivitis, in order to elucidate the basic immunologic mechanisms in the inducton of these ocular diseaes, and the develop methods to prevent or suppress these ocular diseases by manipulating the immune system. The basic experimental design consists of injecting insoluble beads coated with antigen retrobulbarly, intravitreally, or subconjunctivally into normal or sensitized animals. Beads of this size (40 to 60 Mu) lodge in the sites of injection, where they induce a chronic inflammatory reaction, with lymphoproliferative and granulomatous complicatins which will be followed histologically. WE wil then try passive transfer of the lymphoproliferative and granulomatous responses into naive recipients, by injection of lymphoid cells or serum from animals with active disease. Specifically, we hope to define more precisely the nature of the damaging immunologic reactions participating in ocular disease, to characterize the types of cells that mediate inflammatory responses, and to isolate granuloma-derived lymphokines that may contribute to ocular inflammatory reactions. An understanding of the immune mechanisms involvedin the pathogenesis of these ocular diseases is essential to the prevention of tissue damage by such inflammatory processes. A second segment of this proposal will involve attempts to immunosuppress ocular inflammatory disease by manipulating the host's own immune system. Two novel modes of activating suppressor cells will be tested for their ability to eliminate undesired ocular immune reactions: (1) the use of syngeneic cell-bound antigens or idiotypes to augment primary suppressor cell activity, and (2) the passive administration of anti-idiotypic antibodies to stimulate the development of secondary suppressor cells.